Lucas Genzelis
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lgenzelis.bsky.social
Lucas Genzelis
@lgenzelis.bsky.social
26 followers 49 following 30 posts
Tech enthusiast. TS dev. He/Him
Posts Replies Media Videos
Reposted by Lucas Genzelis
b0rk.jvns.ca
redirects

wizardzines.com/comics/termi...

(from "The Secret Rules of the Terminal", out now! wizardzines.com/zines/termin...)
redirect to a file: cmd > file.txt terminal emulator into program, program out to file.txt, error out to terminal emulator append to a file: cmd >> file.txt terminal emulator into program, program out to file.txt (append mode), error out to terminal emulator send a file to stdin: cmd < file.txt file.txt into program, program out and err to terminal emulator redirect stderr to a file: cmd 2 > file.txt terminal emulator into program, program out to nowhere, err out to file.txt redirect stdout AND stderr: cmd > file.txt 2>&1 terminal emulator into program, out and err to file.txt pipe stdout: cmd1 | cmd2 terminal emulator into program 1, 1 out to program 2 via pipe, 2 out to command line, program 2 out 1 and 2 to terminal emulator pipe stdout AND stderr: cmd1 2>&1 | cmd2 terminal emulator into program 1, 1 and 2 out to program 2 via pipe, program 2 out 1 and 2 to terminal emulator three gotchas cmd file.txt > file.txt will delete the contents of file.txt some people use set -o noclobber (in bash/zsh) to avoid this but I just have “never read from redirect to the same file” seared into my memory. sudo echo blah > /root/file.txt doesn’t write to /root/file.txt as root. Instead, do: echo blah | sudo tee /root/file.txt or sudo sh -c 'echo blah > /root/file.txt' cmd 2>&1 > file.txt doesn’t write both stdout and stderr to file.txt. Instead, do: cmd > file.txt 2>&1 cat vs < I almost always prefer to do: cat file.txt | cmd instead of cmd < file.txt it works fine & it feels better to me using cat can be slower if if’s a GIANT file though &> and &| some shells support &> and &| to redirect/pipe both stdout and stderr (also some shells use |& instead of &|)
October 7, 2025 at 3:03 PM
lgenzelis.bsky.social
"Beware The URL Type-Safety Iceberg" by @francoisbest.com on the @nuqs.dev blog • nuqs.dev/blog/beware-...
Beware The URL Type-Safety Iceberg | nuqs
Type-safe URL state is only the visible part. There are more dangers below.
nuqs.dev
September 14, 2025 at 2:22 PM
Reposted by Lucas Genzelis
joshwcomeau.com
✨ I just published a brand-new post! It’s about the notorious SVG <path> element.

With its compact Regex-style syntax, <path> can be super intimidating. But they’re also *incredibly* powerful, letting us draw (and animate!) curved lines.

You can read it here, and I’ll share more info in thread. 🧵
An Interactive Guide to SVG Paths • Josh W. Comeau
SVG gives us many different primitives to work with, but by far the most powerful is the <path> element. Unfortunately, it’s also the most inscrutable, with its compact Regex-style syntax. In this tut...
www.joshwcomeau.com
August 18, 2025 at 3:27 PM
Reposted by Lucas Genzelis
una.im
Wow, I love @joshwcomeau.com's content so much.

And this may be my favorite yet 😍

www.joshwcomeau.com/svg/interact...
An Interactive Guide to SVG Paths • Josh W. Comeau
SVG gives us many different primitives to work with, but by far the most powerful is the <path> element. Unfortunately, it’s also the most inscrutable, with its compact Regex-style syntax. In this tut...
www.joshwcomeau.com
August 19, 2025 at 7:58 PM
lgenzelis.bsky.social
Just read tkdodo.eu/blog/react-q... by @tkdodo.eu ! Awesome read, finally cleared some things about selectors for me. I wanted to leave a comment btw, but comments are not working apparently (I see the call to giscus.app/api/oauth/to... returning a `400`).
React Query Selectors, Supercharged
How to get the most out of select, sprinkled with some TypeScript tips.
tkdodo.eu
August 7, 2025 at 1:04 PM
Reposted by Lucas Genzelis
alois-seckar.cz
Thanks @weeklybrew.dev for sharing this beyond awesome "SVG tutorial" by @joshwcomeau.com. I really learned a lot of new and cool things today. www.joshwcomeau.com/svg/friendly...
A Friendly Introduction to SVG • Josh W. Comeau
SVGs are one of the most remarkable technologies we have access to on the web. They’re first-class citizens, fully addressable with CSS and JavaScript. In this tutorial, I’ll cover all of the most imp...
www.joshwcomeau.com
July 23, 2025 at 8:04 AM
Reposted by Lucas Genzelis
danabra.mov
⚛️📝 New on Overreacted: How Imports Work in RSC
How Imports Work in RSC — overreacted
A layered module system.
overreacted.io
June 5, 2025 at 6:57 PM
Reposted by Lucas Genzelis
danabra.mov
⚛️📝 New on Overreacted: Progressive JSON
Progressive JSON — overreacted
Why streaming isn't enough.
overreacted.io
May 31, 2025 at 4:41 PM
Reposted by Lucas Genzelis
b0rk.jvns.ca
I think I have finally managed to articulate this very fundamental but slightly counterintuitive fact about how shell redirection works
when you redirect, the shell opens the file BEFORE the program starts sudo echo blah > file.txt first I'll open file.txt... THEN I'll run sudo echo blah this is why file.txt isn't opened as root!
May 23, 2025 at 7:07 PM
Reposted by Lucas Genzelis
danabra.mov
⚛️📝 New on Overreacted: Functional HTML
Functional HTML — overreacted
Tags on both sides.
overreacted.io
May 2, 2025 at 3:37 PM
Reposted by Lucas Genzelis
danabra.mov
⚛️📝 New on Overreacted: RSC for Astro Developers
RSC for Astro Developers — overreacted
Islands, but make it fractal.
overreacted.io
May 6, 2025 at 3:36 AM
lgenzelis.bsky.social
Conditional return types just landed, and omg, they're beautiful:
www.typescriptlang.org/play/?ts=5.8...
function f<Kind extends 'single' | 'multiple'>(kind: Kind, items: string[]): {single: string; multiple: string[];}[Kind] { if (kind === 'single') { return items[0]; } return items.slice(0,2); } const one = f('single', []); // ^? const many: string[] = f('multiple', []); // ^?
February 1, 2025 at 8:48 PM
Reposted by Lucas Genzelis
joshuakgoldberg.com
The Open Source Pledge is one of the most exciting initiatives for open source I've seen in years.

Open source funding today is inherently broken. Do the right thing, support open source.

@opensourcepledge.com
January 31, 2025 at 1:03 PM
Reposted by Lucas Genzelis
nerdy.dev
You can now see which value is the active value in min(), max() and clamp()

- in Canary DevTools today
- coming to Chrome stable soon!
font-size: min(2em, 2rem); padding: clamp(10px, 5vw, 30px); margin: max(2lh, 2em); 2em is crossed out 10px, 5vw is crossed out 2em is crossed out
January 30, 2025 at 7:19 PM
Reposted by Lucas Genzelis
joshwcomeau.com
Very cool! 😄
January 17, 2025 at 1:36 AM
lgenzelis.bsky.social
I did it! 🎉 I got the Yeti home at DebugDecember.com
#DebugDecember
Debug December
Help the Yeti get home. Play Debug December and win cool prizes.
DebugDecember.com
December 24, 2024 at 1:18 PM
lgenzelis.bsky.social
I've completed 🎩Bernard's New Demands 2: Electric Boogaloo - Advent of TypeScript 2024 adventofts.com/events/2024/21
Advent of TypeScript
Advent of TypeScript is a month-long event running from December 1 to Christmas, featuring daily TypeScript challenges. Participants can test their skills, climb the leaderboard, and engage with the T...
adventofts.com
December 22, 2024 at 1:05 AM
lgenzelis.bsky.social
I've completed Variable Scope Analysis: 🎩Bernard's New Demands - Advent of TypeScript 2024 adventofts.com/events/2024/20
Advent of TypeScript
Advent of TypeScript is a month-long event running from December 1 to Christmas, featuring daily TypeScript challenges. Participants can test their skills, climb the leaderboard, and engage with the T...
adventofts.com
December 20, 2024 at 2:07 PM
lgenzelis.bsky.social
I've completed The Lazy Elf's Code Generator - Advent of TypeScript 2024 adventofts.com/events/2024/19
Advent of TypeScript
Advent of TypeScript is a month-long event running from December 1 to Christmas, featuring daily TypeScript challenges. Participants can test their skills, climb the leaderboard, and engage with the T...
adventofts.com
December 19, 2024 at 3:05 PM
lgenzelis.bsky.social
Day [18] ✅ I got the Yeti one step closer to home at DebugDecember.com
#DebugDecember
Debug December
Help the Yeti get home. Play Debug December and win cool prizes.
DebugDecember.com
December 18, 2024 at 3:42 AM
lgenzelis.bsky.social
I've completed Mind Control Is Surprisingly Effective - Advent of TypeScript 2024 adventofts.com/events/2024/17
Advent of TypeScript
Advent of TypeScript is a month-long event running from December 1 to Christmas, featuring daily TypeScript challenges. Participants can test their skills, climb the leaderboard, and engage with the T...
adventofts.com
December 17, 2024 at 3:18 PM
Reposted by Lucas Genzelis
srsholmes.com
Good morning Bluesky 👋🏼 🦋

Web Dev / Dev tools tip 🔥

Did you know there is a 'changes' tab in the browser dev tools?

It keeps track of changes that you make and presents it in git style diff UI.

You can even copy changes when you're finished! 🤯

Never lose those unknown CSS changes again 🎉
December 12, 2024 at 10:29 AM
lgenzelis.bsky.social
I've completed 🎩Bernard's Long List Of Names - Advent of TypeScript 2024 adventofts.com/events/2024/12
Advent of TypeScript
Advent of TypeScript is a month-long event running from December 1 to Christmas, featuring daily TypeScript challenges. Participants can test their skills, climb the leaderboard, and engage with the T...
adventofts.com
December 12, 2024 at 5:11 PM
lgenzelis.bsky.social
I've completed Excuses, Excuses - Advent of TypeScript 2024 adventofts.com/events/2024/11
Advent of TypeScript
Advent of TypeScript is a month-long event running from December 1 to Christmas, featuring daily TypeScript challenges. Participants can test their skills, climb the leaderboard, and engage with the T...
adventofts.com
December 11, 2024 at 1:20 PM
Reposted by Lucas Genzelis
joshwcomeau.com
One of my favourite UI patterns is using `backdrop-filter` to create a “frosted glass” effect.

When I see this effect in the wild, though, it’s almost never as lush and realistic as it could be. There’s an important optimization that nobody makes.

✨ I share the secret sauce in my brand-new post:
Next-level frosted glass with backdrop-filter • Josh W. Comeau
Glassy headers have become a core part of the “slick startup” UI toolkit, but they’re all missing that final 10% that really makes it shine. In this tutorial, you’ll learn how to create the most reali...
joshwcomeau.com
December 2, 2024 at 6:18 PM